While the C–H activation field has moved forward dramatically over the last two decades, a recurrent problem lies in the difficulty of activating C–H bonds in the presence of poten­tially much more reactive functional groups, and to do so under conditions where delicate functionalities can survive. Often, new methodologies developed will be applicable to only a small range of simple substrates and fail when facing ‘real world’ molecules bearing a range of functional groups. This is particularly the case for many drug­like molecules, which often contain several polar functionalities, and are therefore not only delicate, but also able to coordinate and poison catalysts. However, being able to directly functionalize C–H bonds of complex molecules is one of the major targets in the field. Late­stage functionalization allows fast access to new molecules and the exploration of new chemical space while avoiding costly de novo syntheses.
Developing milder and more functional­group­tolerant C–H arylation methodologies has been a target of Professor Igor Larrosa’s group at the University of Manchester (UK) from day one.